No idea what ingredients you’d get from kelp farming but it would be cool
Also aquaculture would be cool. You could farm fish (the fish would never be able to leave their cube sadly) and when they grew up you could cook them as food or compact them to get bones (like in Conan Exiles). We definitely could use a way to farm bones.
Nah I think bones is easy to acquire, ive had some for sale for 4.5 and they barely shift, if ya need them I can give you some?
I rather see beans introduced into farming. We don’t need a new ingredient. Fix some of the grind in the existing ingredients.
I like the idea of updating the water biomes, but the OP seems a little too much like Minecraft.
But I’m all for water’ness 
Oehh imagine having fish in your small 36x36 aquarium.
Would be fine if they where random spawns in large water bodies.
And you could fish (for fish and or treasure).
Interesting idea with the bones! Nice!
But yes, this all sounds lovely, fishies in the water please, we can fish them, keep them in separate little areas, etc.
Oh, oh, oh! Just had a nice idea! One of the fish we can keep in a pond and farm them is a really, really fast one which is hard to catch but once you have a bunch of them in an enclosed little pond they reproduce like maniacs and once they die they drop… wait for it… adrenal glands! (or something else that can be used instead of adrenal glands, perhaps their eggs can so we need to decide to use the eggs to create more fish or use them up in a recipe for fast brews!)
And growing kelp and other water plants sounds very good too! Reactive lamellas could be grown like that!!
We also still need to grow beans somehow tho…
Hm what if you could compact meat to get bones? Maybe 2 regular meat to one bone, 1 prime meat to one bone.
Also it would be more interesting if harvesting plants then putting them in the extractor gave more output than “doing it in the field” by hitting the plant with a hammer.